Knowing you can only use 5 large numbers that are right in front of your face one time each is something a 3rd grader could easily accomplish.  Unless the chick in the OP has a disorder, she deserves to be lol'd to death.
		
		
	 
I'm not making any assumptions about the hearing conditions, but Barker kept saying "You use
d the 1 twice" even after it was obvious that the contestant noticed and corrected it. I got an impression that the contestant probably thought he was INSISTING: "You use the 1 twice." ("You [need to] use the 1 twice.")
Really, I wanted Bob to shut up for a second so the person could just assess the situation...then see if the fail continues.